Golf club designers and manufacturers have found that weight adjustment members can be employed to optimize certain characteristics of golf clubs. In particular, weight adjustment members can be used to, among other things, affect the weight of the club, adjust and compensate for variations in manufacturing tolerances, adjust the “feel” of a club, and adjust and enhance vibration characteristics of a golf club. U.S. Pat. No. 6,206,790 to D. J. Kubica et al discloses a representative weight adjustment member for iron-type golf clubs.
The weight adjustment member disclosed in U.S. Pat. No. 6,206,790 is shown to be disposed in a secondary cavity, which is located within a primary cavity that forms the back-side of the club. The weight adjustment member is further described to have a predetermined volume, which may have a plurality of different weights and densities to achieve different attributes.
The soles of many iron-type golf clubs progressively increase in width from heel to toe. That is, the soles of iron-type golf clubs are, typically, greater in width near the toe of the club than near the heel. This design serves many functions including, for example, it helps to prevent unwanted twisting movement about a vertical axis through the body of the golf club head, which may otherwise result when the front face of the club impacts a ball near the toe or heel portions.
Accordingly, some weight adjustment members known in the art have been designed to accommodate the progressive width characteristics of the soles of such iron-type club heads. For example, weight adjustment members have been designed to proportionately increase in width from the portion near the heel-end of the club to the portion near the toe-end of the club. Of course, designing a weight adjustment member in this manner allows the exterior side of the member to remain substantially adjacent to the back-side of the sole as it also increases in width from heel to toe. In this prior art design, however, the depth of the cavity into which the member is disposed in the back-side of the club, preferably, also increases from heel to toe, which is generally required to maintain a relatively constant distance between the member and club face.
Still further, weight adjustment members have been designed with convex, angled backs to accommodate golf club soles with progressive widths. In such case, the cavity into which the member is disposed in the back-side of the club head, preferably, exhibits a complementarily angled, concave surface to receive the member. When this design is employed, the member can be positioned in such a way that allows the exterior surface of the member to remain substantially adjacent to the back-side of the sole as it increases in width from heel to toe.
Of course, the foregoing designs for weight adjustment members require fairly sophisticated molds and manufacturing processes to, for example, create the variability in width and/or angled backs in the members, and, further, may require complex forging or casting procedures to create appropriately configured corresponding cavities in the back-side of golf club heads. Additionally, in some cases, such designs may result in performance differences across the member in light of potential variation in width of the member and/or distance from the club face.
In light of the foregoing, the inventors have discovered certain novel weight adjustment members, which exhibit a substantially linear back-side and a relatively uniform width from the heel to toe portion. In further embodiments of the present invention, the inventors have developed novel weight adjustment members, which exhibit a substantially linear back-side and a symmetrically configured variable width. The inventors have discovered that the weight adjustment members of the present invention may be disposed in a cavity, which is oriented in the back-side of a club head as described herein, to allow the exterior face (a.k.a. the exterior surface) of the member to remain substantially adjacent (or symmetrically aligned) with the surface of the back-side of iron-type clubs from heel to toe.
Because the weight adjustment members of the present invention exhibit (i) a relatively uniform or symmetrically configured width and/or (ii) a substantially linear back-side, the members simplify the methods and molds that are needed to manufacture the same and, of course, the club heads with which such members may be used. The approximately uniform or symmetrically configured width provides a more consistent level of performance across the weight adjustment member and, furthermore, may allow the member to comprise a greater volume.
In still further embodiments of the present invention, novel golf club heads are provided, which comprise at least one cavity in the back-side of the club head, wherein the cavity is approximately equal distance from the club face from its heel- to toe-end. The golf club heads of the present invention, preferably, may be used in connection with at least one weight adjustment member of the present invention.